Hairbrush



FIG. 1 shows a perspective view of our design for a hairbrush;

FIG. 2 shows a side view thereof, with the opposite side being identical;

FIG. 3 shows a side view thereof rotated 90°, with the opposite side being identical;

FIG. 4 shows a front end view thereof; and,

FIG. 5 shows a rear view thereof. 

The ornamental design for a hairbrush, as shown and described. 